Rationalizing the denominator, simply means "getting rid of that pesky root at the bottom", and we do so by simply multiplying it by something to take it out, of course, we multiply the bottom, we have to also multiply the top,

Answer:
17 tenths - 8 tenths=9 tenths
Step-by-step explanation:
1.7 tenths is 17 tenths, we can see that by multiplying 1.7x10 to get 17
dot he sam with 0.8 to get 8 tenths
ti find the answer, subtract the units. 17-8=9
2n-4= n-10
-n. -n
n-4=-10
+4. +4
n=-6
Final answer: -6
The answer is d its decreasing